Encoding and context-dependent control of reward consumption within the central nucleus of the amygdala

Summary Dysregulation of the central amygdala is thought to underlie aberrant choice in alcohol use disorder, but the role of central amygdala neural activity during reward choice and consumption is unclear. We recorded central amygdala neurons in male rats as they consumed alcohol or sucrose. We observed activity changes at the time of reward approach, as well as lick-entrained activity during ongoing consumption of both rewards. In choice scenarios where rats could drink sucrose, alcohol, or quinine-adulterated alcohol with or without central amygdala optogenetic stimulation, rats drank more of stimulation-paired options when the two bottles contained identical options. Given a choice among different options, central amygdala stimulation usually enhanced consumption of stimulation-paired rewards. However, optogenetic stimulation during consumption of the less-preferred option, alcohol, was unable to enhance alcohol intake while sucrose was available. These findings indicate that the central amygdala contributes to refining motivated pursuit toward the preferred available option.

and histograms (bottom) during lick cycles of two example neurons recorded in the same session.A lick cycle is defined as the time between two consecutive contacts with the fluid delivery port (see Methods).The p-value of Rayleigh test is indicated.C) Proportion of neurons significantly modulated by licks (Rayleigh's test with p-value < 0.01).D) Circular histogram of the preferred firing phases (V test against 90°, n=189 lick-modulated neurons, V189 =53.43, p<10 -7 ).E) Heat map of spike probability during lick cycles of lick-modulated neurons.Black dots indicate the preferred firing phases (i.e.modes).F) Average spike probability of lick-modulated neurons across lick cycles (mean±s.e.m.).G) There was no difference between the proportion of lick-modulated neurons recorded from rats with (2-5) or without (6-12) a previous history with alcohol (prev.alcohol exposure: 16/38, no prev.alcohol exposure: 173/354 neurons; binomial proportion test, p=0.43).H) The proportion of lick-modulated neurons is higher during sucrose consumption compared to ethanol (z binomial proportion test, p<10 -6 ).I) The distributions of the preferred firing phases of lick-modulated neurons from ethanol and sucrose consuming rats are not significantly different (Kuiper test, k=2.1090.10 3 , K=1.9931.10 3 , p=0.1).

Figures
Figures S2.Centralamygdala neurons are modulated by licks during the consumption of sucrose, Related to Figure 2. A) Average lick rates during the consumption of 14.2% sucrose for each rat during recording sessions.Smaller symbols indicate lick rate for each individual session.B) Spike rasters (top) and histograms (bottom) during lick cycles of two example neurons recorded in the same session.A lick cycle is defined as the time between two consecutive contacts with the fluid delivery port (see Methods).The p-value of Rayleigh test is indicated.C) Proportion of neurons significantly modulated by licks (Rayleigh's test with p-value < 0.01).D) Circular histogram of the preferred firing phases (V test against 90°, n=189 lick-modulated neurons, V189 =53.43, p<10 -7).E) Heat map of spike probability during lick cycles of lick-modulated neurons.Black dots indicate the preferred firing phases (i.e.modes).F) Average spike probability of lick-modulated neurons across lick cycles (mean±s.e.m.).G) There was no difference between the proportion of lick-modulated neurons recorded from rats with (2-5) or without (6-12) a previous history with alcohol (prev.alcohol exposure: 16/38, no prev.alcohol exposure: 173/354 neurons; binomial proportion test, p=0.43).H) The proportion of lick-modulated neurons is higher during sucrose consumption compared to ethanol (z binomial proportion test, p<10 -6 ).I) The distributions of the preferred firing phases of lick-modulated neurons from ethanol and sucrose consuming rats are not significantly different (Kuiper test, k=2.1090.10 3 , K=1.9931.10 3 , p=0.1).
Figures S2.Centralamygdala neurons are modulated by licks during the consumption of sucrose, Related to Figure 2. A) Average lick rates during the consumption of 14.2% sucrose for each rat during recording sessions.Smaller symbols indicate lick rate for each individual session.B) Spike rasters (top) and histograms (bottom) during lick cycles of two example neurons recorded in the same session.A lick cycle is defined as the time between two consecutive contacts with the fluid delivery port (see Methods).The p-value of Rayleigh test is indicated.C) Proportion of neurons significantly modulated by licks (Rayleigh's test with p-value < 0.01).D) Circular histogram of the preferred firing phases (V test against 90°, n=189 lick-modulated neurons, V189 =53.43, p<10 -7).E) Heat map of spike probability during lick cycles of lick-modulated neurons.Black dots indicate the preferred firing phases (i.e.modes).F) Average spike probability of lick-modulated neurons across lick cycles (mean±s.e.m.).G) There was no difference between the proportion of lick-modulated neurons recorded from rats with (2-5) or without (6-12) a previous history with alcohol (prev.alcohol exposure: 16/38, no prev.alcohol exposure: 173/354 neurons; binomial proportion test, p=0.43).H) The proportion of lick-modulated neurons is higher during sucrose consumption compared to ethanol (z binomial proportion test, p<10 -6 ).I) The distributions of the preferred firing phases of lick-modulated neurons from ethanol and sucrose consuming rats are not significantly different (Kuiper test, k=2.1090.10 3 , K=1.9931.10 3 , p=0.1).

Figure S3 .
Figure S3.Microstructural analysis of consumption indicates optogenetic stimulation of the central amygdala enhances motivation to consume but not palatability of the laser-paired option, Related to Figure 3. A-I) Total number of licks made on each bottle for each of the tests presented in Figure 3. Graphs are organized with the most valued option at the top and leftmost position and the least valued option at the bottom and rightmost position.Comparisons between bottles containing the same offer tile

Figure S4 .
Figure S4.Optogenetic stimulation of the central amygdala during consumption can reverse preference between two isocaloric and objectively equal rewards, Related to Figure 3. A) Consumption in g/kg in tests when sucrose consumption was laser-paired and maltodextrin was not.B) Consumption in g/kg in tests where one bottle containing maltodextrin was laser-paired and the other bottle with maltodextrin was not.C) Consumption in g/kg in tests when maltodextrin consumption was laser-paired and sucrose was not.D-F) Same as A-C but the number of licks made on each bottle.G-I) Same as A-C but the number of clusters of licks made on each bottle.J-L) Same as A-C but the average number of licks made per cluster

Figure S5 .
Figure S5.Microstructural analysis of consumption indicates optogenetic inhibition of the central amygdala does not suppress motivation to consume but suppresses the palatability of the laser-paired option, Related to Figure 5. A-I) Total number of licks made on each bottle for each of the tests presented in Figure 5. Graphs are organized with the most valued option at the top and leftmost position and the least valued option at the bottom and rightmost position.Comparisons between bottles containing the same offer tile the diagonal, bottles above diagonal are tests in which the more valued option was green-

Figure S6 .
Figure S6.Optogenetic inhibition of the central amygdala during consumption cannot reverse preference between two isocaloric and palatable rewards, Related to Figure 5. A) Consumption in g/kg in tests when sucrose consumption was laser-paired and maltodextrin was not.B) Consumption in g/kg in tests where one bottle containing maltodextrin was laser-paired and the other bottle with maltodextrin was not.C) Consumption in g/kg in tests when maltodextrin consumption was laser-paired and sucrose was not.D-F) Same as A-C but the number of licks made on each bottle.G-I) Same as A-C but the number of clusters of licks made on each bottle.J-L) Same as A-C but the average number of licks made per cluster for inhibition-paired option versus the non-paired option.Filled symbols indicate the bottle that resulted in green light delivery, open symbols the other bottle that did not trigger any light delivery.Large symbols